12. Retirement Benefits

Net periodic benefit (credit) cost of our U.S. pension plans (including our unfunded nonqualified plans), non-U.S. pension plans, and postretirement health care and life insurance benefit plans for the three months ended June 30, 2018 and 2017, respectively, follow:



	U.S. Pension Plans				Non-U.S. Pension Plans				Other Benefit Plans
	Three Months Ended June 30,
	2018		2017		2018		2017		2018		2017
	(Dollars in thousands)
Service cost	$	3	$	4	$	447	$	423	$	1	$	—
Interest cost		2,788		3,666		667		606		183		211
Expected return on plan assets		(3,995)		(4,740)		(225)		(222)		—		—
Amortization of prior service cost		—		2		10		11		—		—
Net periodic benefit (credit) cost	$	(1,204)	$	(1,068)	$	899	$	818	$	184	$	211

Net periodic benefit (credit) cost for the six months ended June 30, 2018 and 2017, respectively, follow:



	U.S. Pension Plans				Non-U.S. Pension Plans				Other Benefit Plans

	Six Months Ended June 30,

	2018		2017		2018		2017		2018		2017

	(Dollars in thousands)
Service cost	$	6	$	9	$	908	$	827	$	1	$	—
Interest cost		5,576		7,331		1,356		1,179		366		422
Expected return on plan assets		(7,989)		(9,479)		(459)		(432)		—		—
Amortization of prior service cost		—		3		22		21		—		—
Net periodic benefit (credit) cost	$	(2,407)	$	(2,136)	$	1,827	$	1,595	$	367	$	422

Interest cost, expected return on plan assets and amortization of prior service cost are recorded in Miscellaneous (income) expense, net on the condensed consolidated statement of operations.